Under cover (Pod prikritie) are a real top world class TV series. The only real problem for it to become hit in other countries is that it's in Bulgarian language. That's not actually something that I consider as "bad".
The plot of the movie is quite classical - there is a mafia organization and there is a cop which is undercover. What makes it really different than other "hollywood" movies is: 1. There is no "absolute" (good or bad) characters. Everybody has his own good and bad characteristics. You can see corrupted cops and corrupted judges on the side of the "good guys" and you can see good sides of people in the mafia side.
2. The connections between the different groups is at a very deep level. The series have a good plot.
3. There is always a surprise! The scenarists are definitely feeling what the audience thinks and they are taking well-balanced notes. They definitely know when one character is exhausted and they know when to take it off (killed).
As a summary - the first season is awesome. Very realistic. The second season is not worse, despite the little moving away from the realism. The third season focused more on the action (shootings, chases, etc). It's definitely for a little bit different audience taste, but again - it's not worse than others. What could make a little bad impression in the third season are the "hidden" advertisements. They are not too "hidden" at all...
It's surprising how the producers managed to keep the top level of the series for such a long time with such a low budget. That's a production which deserves to be watched!
